This invention relates to a seismic-resistant support system for upstanding electrical apparatus having a tall slender profile, and, more specifically, relates to a seismic support system of this type that is capable of protecting the upstanding electrical apparatus against severe earthquake forces.
Of interest with respect to this patent application is the following prior art: U.S. Pat. No. 2,711,297 -- Thiele; U.S. Pat. No. 3,592,422 -- Paine; and the Shock and Vibration Handbook by Harris and Crede, published by McGraw-Hill Book Co. in 1961, especially Volume 2, pages 32-7 through 32-10.
Some types of electrical apparatus, such as live-tank circuit breakers, are characterized by a tall slender profile. Prior designs of such apparatus have not been as resistant to damage from earthquake forces as might be desired.
Of interest, further, with respect to the instant problem is an additional U.S. patent, namely U.S. Pat. No. 3,789,174, issued Jan. 29, 1974 to Philip Barkan et al.
The present invention is particularly applicable to upstanding electrical equipment, which is disposed in some areas of the country where seismic vibrations may occur, for instance in California, where relatively recently, that is, Feb. 9, 1971, severe damage was caused by the San Fernando earthquake in California upon building structures and other upstanding equipment including circuit-breakers. As well known by those skilled in the art, at the higher voltages, say 500 kv, 750 kv and 1,000 kv, the installation requirements demand that the upstanding insulating supports be disposed at considerable distances physically above ground level. Since these supports are insulating, in many instances they are formed of porcelain, or other relatively fragile insulating material, which is subject to fracture upon excessive vibration. Moreover, in the case of "live-tank" circuit-breakers, the actual heavy interrupting unit, or head, is disposed at a considerably elevated distance above ground potential, and, again, is subject to seismic vibrations. Accordingly, the present invention is applicable to upstanding electrical equipment, such as circuit-breaker equipment, for example, disposed in areas wherein seismic vibrations may be encountered.